A problem exists in gerotor motors when the valving of the volume chambers does not match the volume change in the volume chambers. For example, as one of the volume chambers becomes a maximum volume transition chamber, the valving of the unit will in some situations continue to communicate high pressure fluid into that volume chamber for some more degrees of rotation. The instantaneous result will be that the volume chamber has begun to decrease while still communicating with high pressure. The valving then shuts off and the chamber decreases further. Because of the overlap in the valving, with no way to relieve pressure in the chamber, the fluid pressure will rise rapidly creating a pressure pulse or spike in that volume chamber. This incorrect timing will result in a number of problems in the gerotor, each of which will have a further detrimental effect on volumetric efficiency and motor smoothness. This problem is not specifically related to gerotor motors, but occurs in all hydraulic machines having a separate valving element.
It is therefore a principal object of this invention to provide transition valving through the use of non-return valves within the gear set of a gerotor motor to correct the aforesaid problems.
These and objects will be apparent to those skilled in the art.